3:73 gear story/question

[James Pierce]

Just got a 70 C10 with turbo auto. On the glovebox door it calls out an option for 3:73 rearend gears. My question is why was it an option and
what would be special about them. Also what was stock if you did not get the option. Cascadeheavychevy.

[john]

3:07 was probably the standard ratio and the optional 3:73 would be listed on the spid.

[zeldman]

Depends on the model. If it is a base model 1970 C-10 then 3:73 was standard and 3:07 was optional gearing.

Three on the tree was standard, T350 automatic was optional.

But in the last 44 years all that could have been changed out.

[Mike C]

But if they put it on the SPID, then it was optional. I agree that 3.07 was most likely the standared gear and the 3.73 optional.

[Keith Seymore]

Originally Posted by john

3:07 was probably the standard ratio and the optional 3:73 would be listed on the spid.

This is exactly correct.

Originally Posted by James Pierce

Just got a 70 C10 with turbo auto. On the glovebox door it calls out an option for 3:73 rearend gears. My question is why was it an option and
what would be special about them.

The reason "why" is because not everyone would want to purchase the base gear. The base gear is usually geared (pun intended) towards better fuel economy or passenger car type usage. Optional gears are offered in case the new owner does a lot of trailering or prefers a bit more pep off the line.

Other than that there is nothing "special" about the 3.73 gears. They are constructed the same way as the base gear and there is nothing more "heavy duty" about them.


K

[James Pierce]

Now that all makes perfect sense. This truck had a canopy on it all its life
and was driven back and forth to work.